Reactors for converting reactants to desirable intermediates or final products come in many sizes and shapes. Chemical engineers spend many hours designing reactor systems to optimize reactor production considering pressure, temperature, flow rates, catalyst cost, reaction kinetics along with balancing many other issues and concerns.
It is commonly understood that a generally uniform distribution of reactants in a catalyst reactor is preferred to avoid hot spots and to avoid the underutilization of catalyst in the reactor. Many inlet designs have been created to improve the distribution of reactants within reactors especially where the reactants are vapor versus liquid. For purposes of this invention, gas and vapor mean the same thing and are generally expressed with the term vapor. One problem with distribution of vapor is that such vapors tend to have higher velocity concentrations away from the center, such as when vapors follow a bend in the piping leading to a reactor. In a reactor arrangement that is fed by a conduit with a significant bend leading into the top or bottom of a reactor, the higher velocities tend to follow the outside of the bend and concentrate along one side of the reactor. Baffles and vanes have been used for years to create back pressure on the inlet stream and cause the reactants to distribute themselves across the reactor. But back pressure concerns and velocity loss are always concerns that counter any efforts at creating an even and balanced flow. Reducing the productivity of a reactor is not part of an attractive solution.
Another common technique is to provide an inert support bed with a thick layer of inert material that create many tortuous paths to the catalyst causing mixing and back pressure to create a level of balance across the body of the reactor. Again, this type of solution creates back pressure and velocity loss and also reduces the available volume of a reactor for catalyst. Committing extra interior space in a reactor for inert material also reduces catalyst performance and the productivity of the system.
What is desired is a technique for creating a balanced distribution of the vaporous reactants across the interior space of a reactor without significantly enlarging the size of the reactor and without impairing the productivity of the reactor system. It is also desirable for the vapors to become spread out to the outside of the reactor in radial flow reactors without adding structure or imposing excessive turbulence or drag on the vapor.